From da115763a03d730d374b5105fb5ded0c90b3329e Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Fri, 1 Apr 2011 15:18:48 -0400 Subject: [PATCH] xen/p2m: Create entries in the P2M_MFN trees's to track 1-1 mappings commit 8c5950881c3b5e6e350e4b0438a8ccc513d90df9 upstream. .. when applicable. We need to track in the p2m_mfn and p2m_mfn_p the MFNs and pointers, respectivly, for the P2M entries that are allocated for the identity mappings. Without this, a PV domain with an E820 that triggers the 1-1 mapping to kick in, won't be able to be restored as the P2M won't have the identity mappings. Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman --- arch/x86/xen/p2m.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 141eb0de8b06..c881ae475e95 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -522,11 +522,20 @@ static bool __init __early_alloc_p2m(unsigned long pfn) /* Boundary cross-over for the edges: */ if (idx) { unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE); + unsigned long *mid_mfn_p; p2m_init(p2m); p2m_top[topidx][mididx] = p2m; + /* For save/restore we need to MFN of the P2M saved */ + + mid_mfn_p = p2m_top_mfn_p[topidx]; + WARN(mid_mfn_p[mididx] != virt_to_mfn(p2m_missing), + "P2M_TOP_P[%d][%d] != MFN of p2m_missing!\n", + topidx, mididx); + mid_mfn_p[mididx] = virt_to_mfn(p2m); + } return idx != 0; } @@ -549,12 +558,29 @@ unsigned long __init set_phys_range_identity(unsigned long pfn_s, pfn += P2M_MID_PER_PAGE * P2M_PER_PAGE) { unsigned topidx = p2m_top_index(pfn); - if (p2m_top[topidx] == p2m_mid_missing) { - unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE); + unsigned long *mid_mfn_p; + unsigned long **mid; + + mid = p2m_top[topidx]; + mid_mfn_p = p2m_top_mfn_p[topidx]; + if (mid == p2m_mid_missing) { + mid = extend_brk(PAGE_SIZE, PAGE_SIZE); p2m_mid_init(mid); p2m_top[topidx] = mid; + + BUG_ON(mid_mfn_p != p2m_mid_missing_mfn); + } + /* And the save/restore P2M tables.. */ + if (mid_mfn_p == p2m_mid_missing_mfn) { + mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_mid_mfn_init(mid_mfn_p); + + p2m_top_mfn_p[topidx] = mid_mfn_p; + p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p); + /* Note: we don't set mid_mfn_p[midix] here, + * look in __early_alloc_p2m */ } } -- 2.39.5